Just had my new combi boiler turned on for first time this evening after kind CORGI man turned on gas for me. Lots of lovely hot water, but my radiators are misbehaving. A bit of history:
I've been renovating this house, which has an old oil fired system still waiting to be ripped out. The old hot water tank is isolated, the two cisterns in the attic are isolated, and the central heating and hot water lines are now tapped into the new boiler.
When I bled the radiators, I opened one stopcock on the ground floor and managed to empty the entire system - perfectly normal. Refilled the system from the filling loop on new boiler, filled all radiators to 1.5 bar. This, one would think, shows that the radiators are all on the same system - perfectly normal. However, with the new boiler on, only the upstairs radiators are warming up
Checking the plumbing that runs from upstairs to downstairs (running past the old boiler) I can feel no increase in temperature, except for a slight warmth at the top of one of the pipes (presumably conduction?) but not at the bottom. No water is flowing downstairs.
I tried isolating all the upstairs radiators (except one which I kept open a crack) but the boiler simply couldn't pump the water round anymore. Seems to me the downstairs rad loop isn't seeing the flow from the new boiler. But given I filled the entire system from the filler loop at the new boiler, how can this suddenly be?
My thoughts, and I'm probably wrong: is there a check valve in the system somewhere preventing flow in the downstairs loop? If so, maybe I need to reverse the water flow to sort it out
Any plumbers out there that've seen this a million times before and can offer any advice?
I've been renovating this house, which has an old oil fired system still waiting to be ripped out. The old hot water tank is isolated, the two cisterns in the attic are isolated, and the central heating and hot water lines are now tapped into the new boiler.
When I bled the radiators, I opened one stopcock on the ground floor and managed to empty the entire system - perfectly normal. Refilled the system from the filling loop on new boiler, filled all radiators to 1.5 bar. This, one would think, shows that the radiators are all on the same system - perfectly normal. However, with the new boiler on, only the upstairs radiators are warming up
Checking the plumbing that runs from upstairs to downstairs (running past the old boiler) I can feel no increase in temperature, except for a slight warmth at the top of one of the pipes (presumably conduction?) but not at the bottom. No water is flowing downstairs.
I tried isolating all the upstairs radiators (except one which I kept open a crack) but the boiler simply couldn't pump the water round anymore. Seems to me the downstairs rad loop isn't seeing the flow from the new boiler. But given I filled the entire system from the filler loop at the new boiler, how can this suddenly be?
My thoughts, and I'm probably wrong: is there a check valve in the system somewhere preventing flow in the downstairs loop? If so, maybe I need to reverse the water flow to sort it out
Any plumbers out there that've seen this a million times before and can offer any advice?
